At 07:16 PM 9/19/2002 -0700, you wrote:

>Still don't believe me?  Ever seen those weighted bicycle wheels with 
>handles on them, used for high school physics demonstrations?  You spin up 
>the wheel, and hand it to someone sitting in the teacher's swivel chair; 
>tilting it will make them rotate one way or the other due to 
>precession.  Now, if you make a new shaft that holds two such wheels and a 
>plate with 3-4 roller blade wheels to couple the tires, so that they 
>always turn in opposite directions at equal speeds, you can demonstrate to 
>yourself that such a device has absolutely no gyroscopic stability -- it 
>completely lacks precession, which is what keeps a gyroscope or top from 
>falling.  In fact, the contrarotating wheels have no more resistance to 
>tilting when spinning than they do when dead still.

Ok, I need to find some spinning wheels on shafts to convince myself of 
that.  I can easily admit I may not be thinking about it correctly...

Does it still apply when the spinning masses are on the same shaft, but NOT 
coupled?  I can see how directly coupling them could let them trade off 
forces, but two wheels (or rotors) spinning independently?

John Carmack

_______________________________________________
ERPS-list mailing list
[EMAIL PROTECTED]
http://lists.erps.org/mailman/listinfo/erps-list

Reply via email to